Dysphagia is a term embracing difficulty occurring during the course of eating foods. Dysphagia occurs in patients having a stroke, degenerative diseases of central nerves and peripheral nerves, traumatic cerebropathy, head and neck tumors, and muscular diseases.
It is reported that dysphagia occurs in 29% to 64% of a stroke patient and in up to 81% of a Parkinson's disease patient. Further, even in the case of a disease not directly causing dysphagia, dysphagia may occur, in which a patient does not properly swallow foods due to overall perception and body states of the patient or external effects such as airway intubation or a tracheotomy. In this case, even though there is a difference in degree for each disease and cause, dysphagia may become a cause of aspiration, pneumonia, dehydration, and malnutrition and lead up to death after all.
Swallowing is constituted by an oral cavity step where foods are put into a mouth, chewed, mixed with saliva to form agglomerates, and pushed into a pharyngeal cavity, a pharyngeal cavity step where the foods flowing into the pharyngeal cavity move to an entrance of an esophagus through a series of movements by delicate coordination of various inner structures of the pharyngeal cavity, such as a sot palate excursion, a hyolaryngeal excursion, a pharyngeal peristalsis, and relaxation of an upper esophageal sphincter, and finally, an inflow step where the foods flow into the esophagus through relaxation of the upper esophagus sphincter.
Among the steps, the oral cavity step is capable of being observed by the naked eye to be relatively precisely evaluated without special equipment. However, in the case of the pharyngeal cavity step, only outwardly finely seen and experienced movement of a neck is present in swallowing, and thus a precise structure or function may be confirmed only by special inspection equipment.
Examples of a known general dysphagia measurement apparatus include a video fluoroscopic swallowing study (VFSS) apparatus and a fiberoptic endoscopic evaluation of swallowing (FEES) apparatus. In the video fluoroscopic swallowing study apparatus, a penetration image is recorded on a fluorescent screen by using an X-ray, and an anatomical structure relating to swallowing is capable of being confirmed by the naked eye. The video fluoroscopic swallowing study apparatus is used to evaluate whether functional abnormality is present while swallowing is performed. In the fiberoptic endoscopic evaluation of swallowing apparatus, a flexible endoscope is inserted through a nose to observe an inner structure of the pharyngeal cavity before and after the foods are swallowed. However, there is a drawback in that functions of the oral cavity and the pharyngeal cavity are not capable of being confirmed when swallowing is performed in practice.
The known dysphagia measurement apparatuses have several limitations in clinical use. First, the known dysphagia measurement apparatuses are large and very costly, and are not apparatuses for measuring only dysphagia, and there is difficulty in installation and use of the apparatuses without cooperation with image medical science and otolaryngology departments. Accordingly, a favorable dysphagia examination is not performed in small scale hospitals or institutions treating dysphagia. Hence, there are many cases where many dysphagia patients are ignored or dysphagia treatment is performed without precise evaluation.
Second, even though a condition of using the video fluoroscopic swallowing study apparatus or the fiberoptic endoscopic evaluation of swallowing apparatus is permitted, there is an exposure to radiation in the case of the video fluoroscopic swallowing study apparatus, and an invasive method of inserting an endoscope through a nose is used in the case of the fiberoptic endoscopic evaluation of swallowing apparatus. Accordingly, a swallowing examination should be performed within a relatively short time, and thus there is difficulty in catching of a dysphagia characteristic of each patient in everyday life.
Meanwhile, in a known dysphagia treatment method, electrical stimulation is applied to dysphagia patients having a reduction in hyoidlarynx excursion and a reduction in relaxation force of the esophagus to treat the patients. Examples of the known dysphagia treatment method include a transcutaneous electrical stimulation (TES) method and a neuromuscular electrical stimulation (NES) method.
The transcutaneous electrical stimulation method is a rehabilitation exercise treatment method in which electrical stimulation is applied to a skin of a portion damaged while a functional task is performed to stimulate nerves and muscles under the skin. In the transcutaneous electrical stimulation method, electrical stimulation is applied to a surface of a neck to induce swallowing, thereby treating dysphagia. However, the transcutaneous electrical stimulation method may be used to treat atrophied muscles or muscles having damaged nerves, but has a limit in that an actual contraction of the muscles does not occur.
In the neuromuscular electrical stimulation method, electrical stimulation is applied to the muscles having any remaining nerve distribution and functions of neurologically damaged muscles to induce muscular contraction, and the application is repeated to increase force of the muscle. The neuromuscular electrical stimulation method is applied to treat dysphagia, in which electrodes are attached to external muscles of a neck relating to swallowing to repeat swallowing and improve a muscular motion during swallowing. Chattanooga VitalSTim is manufactured as a dysphagia treatment apparatus in consideration of a precise position of the muscle to be stimulated among the external muscles of the neck relating to swallowing or a type of stimulation pattern in order to treat dysphagia by the neuromuscular electrical stimulation method.
However, in the known dysphagia treatment methods such as the transcutaneous electrical stimulation method and the neuromuscular electrical stimulation method, appropriacy or an effect of the treatment method is not capable of being monitored. Accordingly, in the case of the patients having a problem in the oral cavity step, appropriacy of treatment, a reaction of the patient, and improvement of a target function are capable of being confirmed by the naked eye. However, there is a problem in that in the case of treatment of dysphagia caused by disorder of the pharyngeal cavity step, whether treatment appropriately affects the reduced function of the pharyngeal cavity, or an effect of treatment is not capable of being immediately confirmed during treatment.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.